Mosquito Massacre

The fish known throughout the world as Mosquitofish, (Gambusia sp) is likely the most introduced fish of all time. For better than one hundred years, policymakers, biologists, epidemiologists and others have been introducing the Western Mosquito fish to environments all over the world; primarily as a biological control for mosquitoes (as their name implies) and the diseases that this nuisance bug is a vector for. The earliest record we could find for them being introduced to a non-native environment was 1905! A fish that was originally found in the southern Mississippi drainage, can now be found on every continent in the world save Antarctica.

Gambusia genus fish are nearly miraculous in their hardiness. They thrive in an astounding range of environments, from freshwater to brackish, in pH ranges from sub 6.0 to over 8.0. They are tolerant of pollution loads that would wipe out most fish, can take endure salt loads higher than seawater for extended periods and are completely fine with dissolved oxygen levels that are better suited for lungfish. They can live in very warm climates; they've been shown to survive exposure to temps over 100 degrees and even over 105 for short periods. For reference, 104 is a very common temperature for hot tubs. The limit to this hardiness is the cold side, they do not do well in temperatures below 50 degrees Fahrenheit. In short, they can not only live, but thrive in many waters where mosquitoes reproduce most effectively, and many other fish cannot.

As this relates to the home aquarium or pond parameters, you won't need to tune your water profile or maintenance for the Gambusia, they'll be just fine in whatever you put them in as long as it is relatively close to a normal aquarium set up. A pair of Gambusia makes an almost perfect first couple of fish for new aquarists, even for very small desktop displays. You could keep a couple in a tank as small as a couple gallons without problems because the rarely get bigger than two or three inches long. Though you'll soon have many more fish than that, and a bigger aquarium or harvesting of fry will have to happen. These displays can be whatever you want them to be. Want pink rocks and a bubble chest? Perfect. Perhaps you prefer a densely planted and immaculately groomed display? The Mosquito Fish will be just as happy to breed in there. Heck, they're a much better choice for a fishbowl than goldfish ever were!

Mosquito fish breed so well that they are nearly impossible to stop from doing so. Females bear up to 100 live young which can take surprisingly large food, another trait that makes them so successful. The females in this genus reach sexual maturity in only a few weeks after hatching and can start to reproduce themselves. For the home hobbyist, if you have a male and a female, they will reproduce and the babies can / will take any food small enough to get in their mouths, including most powdered pellets! In fact, the only way your fish won't rapidly grow in numbers is if the fry cannot hide from their parents as this species is known for being wretchedly bad at rearing fish and will pretty much always eat the fry if they can. Basically, Mosquito Fish have quickly established large breeding populations everywhere they have been introduced as long as the winter is mild enough for them to survive! They are so easy to breed and rear that they are also one of the most popular fish for home aquarists to raise as food for both saltwater and freshwater carnivorous fish.

Mosquito fish are voracious predators of just about everything, especially eggs, larvae, small fish and invertebrates near the top of the water column. While near surface feeding is a preference, they will consume pretty much anything they can, from everywhere in the water column. It is this blend of all their characteristics that has made them so popular as mosquito control mechanism. It isn't that they prefer to eat mosquito larvae, it's that they eat voraciously, primarily in the zone where mosquitoes lay eggs and where the larvae grow. Mosquito Fish thrive and reproduce quickly in that same environment and as such, have been very effective in this role.

While many people keep mosquito fish as aquarium pets (and as referenced as food for other fish), they are even more popular for outdoor water features. Many people stock them in their ponds to help control mosquito population; a job (obviously) well suited for the mosquito fish. If your pond is healthy enough to include other fish, the Gambusia will need no particular attention to get them established. This being said, there are a few things to be conscious of with keeping mosquito fish. The same traits that make them so good at wiping out mosquito populations gives them a high potential for being an invasive species, especially in warm climates, so take care to limit the potential for their escape. In colder climates, your mosquito fish will not overwinter, and you'll need to restock them in the spring, which is easily accomplished by bringing a few inside to live out the winter in a holding tank. The nonselective nature of their predation can also be a factor in algal blooms as the Gambusia eat the zooplankton that would usually consume phytoplankton, but sadly don't eat the phyto too. This “I'll eat anything” attitude means they can also limit or even eliminate the reproduction of other fish and amphibians like frogs that you may want in your pond.

Gambusia sp and their voracious appetite with uncanny hardiness, and their jaw-dropping ability to rapidly reproduce makes them likely the best biological mosquito control you can buy for your pond. While there are other fish available to help with this, like Guppies, Tilapia, Bettas and others though none are quite as voracious as the Mosquito Fish. Though for those of you looking for a gentler approach, some of these other species might also be worth looking into. Pond season is in full swing right now, and it is definitely time to start thinking about your pond this year. If you're looking for “set it and forget it” mosquito control, an easy fish for a beginner fish keeper in the house, or even a food culture for your other wet pets, give your pond store or LFS a shout and ask them about Gambusia species from Aquatropic today.